Printer friendly version

Equipment grounding conductor verification and testing on cord and plug-connected equipment

A technician working near a 480Y/277 volt three-phase welder was shocked on May 27 when his elbow contacted the welder cart as he was operating a grounded bandsaw. The plug connection of the welder had recently been incorrectly wired so that the green-insulated, or bare copper equipment-grounding conductor, was connected to one of the energized phases. The installer had been distracted because of being assigned multiple concurrent jobs and the wiring had not been checked or verified prior to being put into service. This resulted in the welder frame and cart being at a nominal 277 volts, relative to ground.

The miswired electrical welder was an imminent danger electrical hazard, waiting for someone to touch it who also was touching a grounded object, completing the circuit path. This situation could have resulted in a severe shock or electrocution.

To read the notice, click here. (Adobe Acrobat Reader required)

Other Headlines